The use of certain types of suppressive shielding for the containment of explosive blasts is known. For example vented blasting mats have long been used in quarry operations to confine detonation effects. The design of such mats was primarily achieved through trial and error. More recently the application of suppressive shielding has been considered for use in other commercial and military applications.
In military applications suppressive shielding development has been generally directed to the containment of an expolsion within a shielding. The blast, fragments and fireball which accompany such a contained explosion, for example the detonation of a round used for a large caliber weapon, can be considered a worst case test for a shielding container, therefore success in such an application would allow the use of such shielding--in a reversed mode--to protect from an exterior threat.
An explosive suppressive shielding has many important applications. For example, such shielding can be used in transportation terminals such as airports and bus stations where terrorist-type attacks can occur. The shields may take many forms in such an application. For instance, a suppressive shielding container may be used for explosives storage at baggage checkpoints. Such a shielding container may also be made to be placed on an aircraft where any explosive device could be placed until proper evacuation is possible.
Larger suppressive structures may be used to provide protection where a greater area of suppression is desired. Thus, a shielding barrier type jacket may be placed around wall lockers at an airport.
Of course, applications for such a shield are not limited to airports and other transportation facilities. In an industrial plant, for example, equipment subject to explosion may be surrounded by a suppressive shield in order to protect workers. Where it is desired to protect an enclosure from outside explosion, such a shield may be reversed, so that occupants in an industrial control room could be protected.
Such vented suppressive shielding also has military applications. Explosive devices may be stored within a shielded container or larger shields may be used to surround explosive storage areas. As with industrial applications, and more so with military uses, the suppressive shielding can be reversed to provide protection for equipment and personnel from explosive detonations occurring outside the barrier. Such a shielding barrier requires that the shield have the ability to withstand not only high pressure waves and a fireball, but also high velocity frgments that invariably are part of military munitions.
Where transportation of dangerous explosives is necessary, shielding is especially desirable. This is true, for example, with the transportation of dynamite and percussion caps to the area of use. In this instance a suppressive shielding container must be relatively small and lightweight.
The problem of providing a useful suppressive shielding are many. Concrete revetments/walls and steel shelters can often provide sufficient shielding, but are too bulky and heavy to provide the various types of protection mentioned above. Such shields often inhibit movement of people or machines because of their large size. Also, the construction of portable shields of these materials is not possible because of their weight and bulk.
Because of the foregoing there has been a need for a suppressive shielding which is relatively light and not bulky, but which will still provide sufficient protection from the blast pressure, heat, flame and fragments which may accompany an explosion.